Pass a Variable in Shortcode to PHP File?

Dear Michael,

Your plugin has been a lifesaver. Thank you. This question may be beyond what you can provide in terms of support, but it is worth a shot:

At present, I have a shortcode that pulls in a php file, like so:

[file]

What I need to do now is connect to a php file that pulls in data according to specific post, i.e., ID, and to do that, I need to pass along the ID of the post in the shortcode so that is looks something like:

[file, ID=224]

That way, when the php file is pulled into the post, it pulls content from the post specified in the shortcode.

Ideas on if and how this can be done, meaning how I would deliver a variable value via shortcode?

Many thanks.

Cheers,

Tim